These tiger lilies bloom every year in the back yard and they are beautiful. I was looking on some sites, and they are an actual wildflower that grows quite easily in ditches throughout America. They do well in moist soil, thus the natural propagation in ditches.

Brightly colored Tiger Lilies.

They also have medicinal qualities which I did not know about. Apparently they can aid with congestion, and the nausea and vomiting associated with pregnancy.